title: Evaluation of the pulsed discharge helium ionization detector for the analysis of hydrogen and methane in breath.
mesh_terms: D001944:Breath Tests / Q000295:instrumentation*; D006371:Helium / Q000737:chemistry*; D006801:Humans; D006859:Hydrogen / Q000032:analysis*; D008697:Methane / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D006371:Helium; D006859:Hydrogen; D008697:Methane